7 years old Worcester Bosch 28CDi (with 2 speed fan I believe)
I’ve had intermittent CH problem since switching on CH after summer, before was ok. DHW is great- no problems. When CH is switched on (timer or manual) it works for a couple of minutes ,I can feel temperature in radiators start to rise a bit , then boiler stops with rapid flashing warning(5flash per second) on DHW demand (red LED). I reset it by power off/on switch, same thing happens stays on for a couple of minutes then fails, but when I reset again fault goes away and CH stays on all evening giving good heat ,running quietly. Fault only occurs when CH first switched on for the day.
I’ve checked flue for blockage and APS air pipes which have no cracks and no condensation. Manual says it’s fail point J –Air pressure fault. Was thinking of replacing APS and then if no good calling out WBosch in case it’s PCB failure but has anybody seen this fault before or any ideas what it could be. Can sludge cause this?
Cold pressure 1.2 bar hot 1.5
I’ve had intermittent CH problem since switching on CH after summer, before was ok. DHW is great- no problems. When CH is switched on (timer or manual) it works for a couple of minutes ,I can feel temperature in radiators start to rise a bit , then boiler stops with rapid flashing warning(5flash per second) on DHW demand (red LED). I reset it by power off/on switch, same thing happens stays on for a couple of minutes then fails, but when I reset again fault goes away and CH stays on all evening giving good heat ,running quietly. Fault only occurs when CH first switched on for the day.
I’ve checked flue for blockage and APS air pipes which have no cracks and no condensation. Manual says it’s fail point J –Air pressure fault. Was thinking of replacing APS and then if no good calling out WBosch in case it’s PCB failure but has anybody seen this fault before or any ideas what it could be. Can sludge cause this?
Cold pressure 1.2 bar hot 1.5